Einab moktebttd



y 0 1933- E. MORTERUD Re. 18,845

BOTTOM SIEVE FOR WQOD'PULF DIGESTERS Original Filed Dec. 26, 1930Reiuued May 30.1933

UNITED STATES PATENT OFFICE EILN'AB MORTERUD, OF TORDEBDD, NEAR MOSS,NORWAY 1 no'r'rom smvr: ron woonrurr monsrnns Original 110. 1,838,848,.dated November 24, 1931, Serial No. 504,804, filedDecember B8, 1930,and in Norway August 19, 1930. Application for reissue-filed 'ihme 14,1932. Serial 80.617.831-

The present invention relates to the type of wood pulp digesters, inwhich the circulation conduit forthe digesting liquor is connected withan annular sieve located near the out- I letopening of the digester, andthe object of the invention is to provide a sieve arrangement ,by meansofwhich it is made possible for the sieve to expand and contract freelyunder the influence of temperature variations, whereas on the other handthe arrange ment of the sieve is such that it is not likely to causecongestion of the pulp near the outlet or prevent the easy emptying ofthe dister. This. is obtained in accordance with t e present inventionby that the. annular sieve is only secured-to the digester proper at onepoint of its circumference, whereas it is .supported at other points ofits circumference in such a manner that a free movement 30 of the sievemay take place with regard to the-digester.

Two forms of the on the drawing.

Figs. 1 and 2 area'xialisectional view and plan of one form of theinvention, and 7 Figs; 3 and 4 are corresponding views of another formof the invention.

invention are illustrated According to the forms illustrated on Fig.

Q 1, 1 is the bottom sieve, which may be in the form of a closed annularor polygonal body and which is connected at one point of itscircumference with the circulation conduit 2 leading to the circulationpump. At or adjacent the connecting point with the conduit or tube 2 theannular sieve 1 is secured to the digester 3 by means of a. stay 4,which is firmly secured to the shell of the digester, and ata number ofother pointsof its circumference the annular sieve is sup orted by meansof 40. pins or rods 5, both ends of which rest in formed integral withthe interior of the digester and serving to conduct the pulp over andpast the sieve during the emptying of the digester. According to thisform of the invention the sieve is also firmly secured to the digestershell at a point adjacent the place at which the circulation conduit 2is connected (bolt 4),whereas on the rest of its circumference it isplaced loosely on brackets or shelves as indicated at 9, permit ting thesieve to expand and contract freely.

I claim':

1. In a wood conduit for the igesting liquor, a sieve of substantiallyannular shape connected with said circulation conduit and located in thelower part of the digester near the outlet opening thereof,andsupporting means for said sieve pivotally connected with the digesterwalls so' as to permit movements of the said sieve with regard to thedigester in a lane parallel to the plane of the annular sieve body.

2. In a wood ulp digester a circulation conduit for the digestingliquor, a sieve connectedwith said circulation conduit and lo: .cated,in the lower part of the digester near the outlet opening thereof, andsupportin means for said sieve pivotally connected wit the digesterwallsso as to permit movements of the said sieve with regard to thedigester body name.

EINAR MO RTERUD. 1. 9.

spherical bearings 6, 7 so as to permit the pins or rods to swing freelyin all directions. Instead of being supported by pins or rods asillustrated the sieve may also be supported 0 and is coated below astationary abutment 8 ulp digester a circulation v ,in a plane paralleltothe plane or the sieve I ID tGStlmOIIY whereof have signed my

